KM Ashikur Rahman, Mohd Saif Shaikh, Qianao Yue, S. Senali Dissanayake, Mao Wang, Shengqiang Zhou, Meng-Ju Sher
Tellurium-hyperdoped silicon (Si:Te) shows significant promise as an intermediate band material candidate for highly efficient solar cells and photodetectors. Time-resolved THz spectroscopy (TRTS) is used to study the excited carrier dynamics of Si hyperdoped with 0.5, 1, and 2%. The two photoexcitation wavelengths enable us to understand the temperature-dependent carrier transport in the hyperdoped region in comparison with the Si region. Temperature significantly influences the magnitude of transient conductivity and decay time when photoexcited by light with a wavelength of 400 nm. Due to the differential mobilities in the Si and hyperdoped regions, such dependence is absent under 266-nm excitation. Consistent with the literature, the charge-carrier lifetime decreases with increasing dopant concentration. It is found that the photoconductivity becomes less temperature-dependent as the dopant concentration increases. In the literature, the photodetection range of Si:Te extends to a wavelength of 5.0 µm at a temperature of 20 K. The simulation shows that carrier diffusion, driven by concentration gradients, is strongly temperature dependent and impacts transient photoconductivity decay curves. The simulation also revealed that, in the hyperdoped regions, the carrier recombination rate remains independent of temperature.
{"title":"Temperature-Dependent Dynamics of Charge Carriers in Tellurium Hyperdoped Silicon","authors":"KM Ashikur Rahman, Mohd Saif Shaikh, Qianao Yue, S. Senali Dissanayake, Mao Wang, Shengqiang Zhou, Meng-Ju Sher","doi":"10.1002/aelm.202400417","DOIUrl":"https://doi.org/10.1002/aelm.202400417","url":null,"abstract":"Tellurium-hyperdoped silicon (Si:Te) shows significant promise as an intermediate band material candidate for highly efficient solar cells and photodetectors. Time-resolved THz spectroscopy (TRTS) is used to study the excited carrier dynamics of Si hyperdoped with 0.5, 1, and 2%. The two photoexcitation wavelengths enable us to understand the temperature-dependent carrier transport in the hyperdoped region in comparison with the Si region. Temperature significantly influences the magnitude of transient conductivity and decay time when photoexcited by light with a wavelength of 400 nm. Due to the differential mobilities in the Si and hyperdoped regions, such dependence is absent under 266-nm excitation. Consistent with the literature, the charge-carrier lifetime decreases with increasing dopant concentration. It is found that the photoconductivity becomes less temperature-dependent as the dopant concentration increases. In the literature, the photodetection range of Si:Te extends to a wavelength of 5.0 µm at a temperature of 20 K. The simulation shows that carrier diffusion, driven by concentration gradients, is strongly temperature dependent and impacts transient photoconductivity decay curves. The simulation also revealed that, in the hyperdoped regions, the carrier recombination rate remains independent of temperature.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"223 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anastasiia S. Kudriavtseva, Nikita P. Nekrasov, Dmitry V. Krasnikov, Albert G. Nasibulin, Alexey M. Bogdanov, Ivan Bobrinetskiy
Bionanohybrids of carbon nanotubes and fluorescent proteins (FPs) are a promising class of materials for optoelectronic applications. Understanding and controlling the charge transport mechanism between FPs and carbon nanotubes are critical to achieving functional reproducibility and exploring novel synergetic effects. This work demonstrates a novel phenomenon of photocurrent generation in field-effect transistors based on the conjugation of an individual single-walled carbon nanotube (SWCNT) and FPs. When studying the effect of gate voltage on the photoresponse, reversible switching from fast positive to a slow negative photoresponse in bionanohybrids associated with depletion and accumulation modes, respectively is observed. The latter demonstrates a stable memory effect after the light is turned off. It is revealed that in depletion mode, the charge carriers from the protein are not trapped at the interface due to effective screening by the gate potential. It is suggested that the main mechanism in photoresponse switching is a competitive effect between photogating and effective photodoping of the SWCNT by charges trapped at the nanotube interface. The noticeable effect of water molecules can support proton transfer as the main mechanism of charge transfer. This result illustrates that SWCNT/FP bionanohybrids bear great potential for the realization of novel optoelectronic devices.
{"title":"Gate-Controlled Photoresponse in an Individual Single-Walled Carbon Nanotube Modified with a Fluorescent Protein","authors":"Anastasiia S. Kudriavtseva, Nikita P. Nekrasov, Dmitry V. Krasnikov, Albert G. Nasibulin, Alexey M. Bogdanov, Ivan Bobrinetskiy","doi":"10.1002/aelm.202400329","DOIUrl":"https://doi.org/10.1002/aelm.202400329","url":null,"abstract":"Bionanohybrids of carbon nanotubes and fluorescent proteins (FPs) are a promising class of materials for optoelectronic applications. Understanding and controlling the charge transport mechanism between FPs and carbon nanotubes are critical to achieving functional reproducibility and exploring novel synergetic effects. This work demonstrates a novel phenomenon of photocurrent generation in field-effect transistors based on the conjugation of an individual single-walled carbon nanotube (SWCNT) and FPs. When studying the effect of gate voltage on the photoresponse, reversible switching from fast positive to a slow negative photoresponse in bionanohybrids associated with depletion and accumulation modes, respectively is observed. The latter demonstrates a stable memory effect after the light is turned off. It is revealed that in depletion mode, the charge carriers from the protein are not trapped at the interface due to effective screening by the gate potential. It is suggested that the main mechanism in photoresponse switching is a competitive effect between photogating and effective photodoping of the SWCNT by charges trapped at the nanotube interface. The noticeable effect of water molecules can support proton transfer as the main mechanism of charge transfer. This result illustrates that SWCNT/FP bionanohybrids bear great potential for the realization of novel optoelectronic devices.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"11 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Orbitronics is an emerging domain within spintronics, and it is characterized by a rapid development of methods for utilizing orbital current. Metals with strong spin-orbit coupling have been effectively used to convert orbital current into orbital torque. This study introduces a metallic [W/Ti]3 superlattice that uses orbital current to significantly enhance the magnetization switching efficiency. The enhancement in torque efficiency is demonstrated via spin-torque ferromagnetic resonance along with the extraction of damping-like (ξDL) and field-like spin-orbit torque (SOT) efficiencies. ξDL for superlattices is more than 100 times higher than that for Pt. As a result, the critical switching current density of the superlattice becomes two orders of magnitude lower than that of Pt. This is primarily attributed to the orbital current generated by the orbital Rashba–Edelstein effect at the W/Ti interface. The thickness of Ti and W layers is modulated to develop a novel approach to utilize orbital current for augmenting SOT efficiency and magnetization switching efficiency in superlattices. The findings of this study provide a basis for developing low-power-consumption memory devices and memory with controllable critical current density in SOT-magnetic random-access memory applications.
轨道电子学是自旋电子学中的一个新兴领域，其特点是利用轨道电流的方法发展迅速。具有强自旋轨道耦合的金属已被有效地用于将轨道电流转化为轨道转矩。本研究介绍了一种金属 [W/Ti]3 超晶格，它利用轨道电流显著提高了磁化切换效率。扭矩效率的提高是通过自旋扭矩铁磁共振以及阻尼样（ξDL）和场样自旋轨道扭矩（SOT）效率的提取来证明的。超晶格的ξDL 是铂的 100 多倍。因此，超晶格的临界开关电流密度比铂低两个数量级。这主要归因于 W/Ti 界面的轨道 Rashba-Edelstein 效应产生的轨道电流。通过调节 Ti 层和 W 层的厚度，开发出一种利用轨道电流提高超晶格中 SOT 效率和磁化切换效率的新方法。这项研究的发现为开发低功耗存储器件和在 SOT 磁性随机存取存储器应用中具有可控临界电流密度的存储器奠定了基础。
{"title":"Orbital Current Boosting Magnetization Switching Efficiency in Metallic Superlattices","authors":"Junwen Wei, Xinkai Xu, Zijin Lin, Yuanjing Qu, Xiaoli Tang, Zhiyong Zhong, Huaiwu Zhang, Lichuan Jin","doi":"10.1002/aelm.202400314","DOIUrl":"https://doi.org/10.1002/aelm.202400314","url":null,"abstract":"Orbitronics is an emerging domain within spintronics, and it is characterized by a rapid development of methods for utilizing orbital current. Metals with strong spin-orbit coupling have been effectively used to convert orbital current into orbital torque. This study introduces a metallic [W/Ti]<sub>3</sub> superlattice that uses orbital current to significantly enhance the magnetization switching efficiency. The enhancement in torque efficiency is demonstrated via spin-torque ferromagnetic resonance along with the extraction of damping-like (<i>ξ</i><sub>DL</sub>) and field-like spin-orbit torque (SOT) efficiencies. <i>ξ</i><sub>DL</sub> for superlattices is more than 100 times higher than that for Pt. As a result, the critical switching current density of the superlattice becomes two orders of magnitude lower than that of Pt. This is primarily attributed to the orbital current generated by the orbital Rashba–Edelstein effect at the W/Ti interface. The thickness of Ti and W layers is modulated to develop a novel approach to utilize orbital current for augmenting SOT efficiency and magnetization switching efficiency in superlattices. The findings of this study provide a basis for developing low-power-consumption memory devices and memory with controllable critical current density in SOT-magnetic random-access memory applications.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"11 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yashar Azizian‐Kalandaragh, Ali Barkhordari, Yosef Badali
This work uses the Support Vector Machine (SVM) to predict the main electronic variables of metal‐semiconductor (MS) and metal‐nanocomposite‐semiconductor (MPS) configurations, i.e., leak current (I0), the height of the potential barrier (ΦB0), ideality coefficient (n), series/shunt resistances (Rs/Rsh), rectification ratio (RR), and surface/interface states density (Nss), along with current conduction/transport mechanisms occurred into them at the reverse/forward biases by analyzing the I–V measurements. The polyvinyl chloride (PVC) and samarium oxide (Sm2O3) nanoparticles are combined to form the two interfacial layers. To analyze the I–V characteristics and train the SVM, the thermionic emission theorem is used. By contrasting the predicted and experimental results, the predictive ability of the SVM approach for predicting the electronic specifications of the fabricated structures and their current conduction/transport processes has been evaluated to investigate the effectiveness of the SVM. There is strong agreement between the experimental data and the SVM predictions of the fundamental electronic characterizations of the MS and MPS structures and the current conduction processes in them at the forward/reverse biases. Additionally, the results demonstrate that the RR value of the MS configuration increases 4 and 53 times if the pure PVC and PVC:Sm2O3 composite interlayers are employed.
{"title":"Support Vector Machine for Prediction of the Electronic Factors of a Schottky Configuration Interlaid with Pure PVC and Doped by Sm2O3 Nanoparticles","authors":"Yashar Azizian‐Kalandaragh, Ali Barkhordari, Yosef Badali","doi":"10.1002/aelm.202400624","DOIUrl":"https://doi.org/10.1002/aelm.202400624","url":null,"abstract":"This work uses the Support Vector Machine (SVM) to predict the main electronic variables of metal‐semiconductor (MS) and metal‐nanocomposite‐semiconductor (MPS) configurations, i.e., leak current (I<jats:sub>0</jats:sub>), the height of the potential barrier (Φ<jats:sub>B0</jats:sub>), ideality coefficient (n), series/shunt resistances (R<jats:sub>s</jats:sub>/R<jats:sub>sh</jats:sub>), rectification ratio (RR), and surface/interface states density (N<jats:sub>ss</jats:sub>), along with current conduction/transport mechanisms occurred into them at the reverse/forward biases by analyzing the I–V measurements. The polyvinyl chloride (PVC) and samarium oxide (Sm<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>) nanoparticles are combined to form the two interfacial layers. To analyze the I–V characteristics and train the SVM, the thermionic emission theorem is used. By contrasting the predicted and experimental results, the predictive ability of the SVM approach for predicting the electronic specifications of the fabricated structures and their current conduction/transport processes has been evaluated to investigate the effectiveness of the SVM. There is strong agreement between the experimental data and the SVM predictions of the fundamental electronic characterizations of the MS and MPS structures and the current conduction processes in them at the forward/reverse biases. Additionally, the results demonstrate that the RR value of the MS configuration increases 4 and 53 times if the pure PVC and PVC:Sm<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> composite interlayers are employed.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"23 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zheng Wang, Mingzhen Zhang, Donggang Xie, Zhuohui Liu, Ge Li, Jiahui Xie, Erjia Guo, Meng He, Can Wang, Guozhen Yang, Kuijuan Jin, Chen Ge
Inspired by neurobiological learning rules, bionic devices that simulate the fundamental functions of synapses and neurons provide a highly effective approach to neuromorphic computing. Among various learning rules, the Bienenstock-Cooper-Munro (BCM) learning rule can explain the threshold sliding effect of synaptic weight modification in the visual cortex, which is difficult to explain with the classical Hebb's rule. Existing research mainly focuses on exploiting electrical stimulation to implement the BCM rule, while the optical implementation is still unexplored. In this paper, the light-history-dependent BCM learning rule is implemented with electrolyte-gated InGaZnO (IGZO) transistors. The channel conductance can be modulated through light illumination and electrical stimulation. By utilizing the light-history-dependent property of the IGZO electrolyte-gated transistor and following the triplet-spike-timing-dependent plasticity (STDP) rules, the BCM learning rule is successfully emulated in a single device. Moreover, the light-history-dependent property enables a variety of bionic vision functions including image edge detection and associative memory. This work provides a paradigm for the novel implementation of the BCM rule and paves the way for further development of machine vision systems.
{"title":"An Electrolyte-Gated InGaZnO Phototransistor that Emulates Visual Experience-Dependent Plasticity","authors":"Zheng Wang, Mingzhen Zhang, Donggang Xie, Zhuohui Liu, Ge Li, Jiahui Xie, Erjia Guo, Meng He, Can Wang, Guozhen Yang, Kuijuan Jin, Chen Ge","doi":"10.1002/aelm.202400612","DOIUrl":"https://doi.org/10.1002/aelm.202400612","url":null,"abstract":"Inspired by neurobiological learning rules, bionic devices that simulate the fundamental functions of synapses and neurons provide a highly effective approach to neuromorphic computing. Among various learning rules, the Bienenstock-Cooper-Munro (BCM) learning rule can explain the threshold sliding effect of synaptic weight modification in the visual cortex, which is difficult to explain with the classical Hebb's rule. Existing research mainly focuses on exploiting electrical stimulation to implement the BCM rule, while the optical implementation is still unexplored. In this paper, the light-history-dependent BCM learning rule is implemented with electrolyte-gated InGaZnO (IGZO) transistors. The channel conductance can be modulated through light illumination and electrical stimulation. By utilizing the light-history-dependent property of the IGZO electrolyte-gated transistor and following the triplet-spike-timing-dependent plasticity (STDP) rules, the BCM learning rule is successfully emulated in a single device. Moreover, the light-history-dependent property enables a variety of bionic vision functions including image edge detection and associative memory. This work provides a paradigm for the novel implementation of the BCM rule and paves the way for further development of machine vision systems.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"1 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jimin Jeong, Yeon Su Park, Min-Gu Kang, Byong-Guk Park
Voltage-controlled magnetism (VCM) offers an efficient operating method for various spintronic applications, with reduced power consumption compared to conventional current-driven technologies. Among the VCM mechanisms, magneto-ionic control provides large modulation and non-volatile characteristics. However, its operating speed is limited to a microsecond timescale due to slow ion migration, which must be improved for practical device applications. Here, the nanosecond operation of magneto-ionic VCM in a Ta/CoFeB/MgO/AlOx structure by introducing an HfO2 gate oxide with resistive switching characteristics is demonstrated. By inducing soft breakdown in the HfO2 gate oxide, the coercivity of the perpendicularly magnetized CoFeB can be controlled by 20% with a 20 ns gate voltage of ≈7 MV cm−1. This nanosecond magneto-ionic VCM performance is maintained after repeated operations up to 10 000 cycles. Further, by utilizing an HfO2 gate in a spin-orbit torque (SOT) device, the ability to control field-free SOT switching polarity with nanosecond gate voltages is demonstrated. These findings provide a novel pathway to realize nanosecond, non-volatile VCM for low-power spintronic applications.
{"title":"Nanosecond Magneto-Ionic Control of Magnetism Using a Resistive Switching HfO2 Gate Oxide","authors":"Jimin Jeong, Yeon Su Park, Min-Gu Kang, Byong-Guk Park","doi":"10.1002/aelm.202400535","DOIUrl":"https://doi.org/10.1002/aelm.202400535","url":null,"abstract":"Voltage-controlled magnetism (VCM) offers an efficient operating method for various spintronic applications, with reduced power consumption compared to conventional current-driven technologies. Among the VCM mechanisms, magneto-ionic control provides large modulation and non-volatile characteristics. However, its operating speed is limited to a microsecond timescale due to slow ion migration, which must be improved for practical device applications. Here, the nanosecond operation of magneto-ionic VCM in a Ta/CoFeB/MgO/AlO<sub>x</sub> structure by introducing an HfO<sub>2</sub> gate oxide with resistive switching characteristics is demonstrated. By inducing soft breakdown in the HfO<sub>2</sub> gate oxide, the coercivity of the perpendicularly magnetized CoFeB can be controlled by 20% with a 20 ns gate voltage of ≈7 MV cm<sup>−1</sup>. This nanosecond magneto-ionic VCM performance is maintained after repeated operations up to 10 000 cycles. Further, by utilizing an HfO<sub>2</sub> gate in a spin-orbit torque (SOT) device, the ability to control field-free SOT switching polarity with nanosecond gate voltages is demonstrated. These findings provide a novel pathway to realize nanosecond, non-volatile VCM for low-power spintronic applications.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"219 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aleksandra Koroleva, Thoai-Khanh Khuu, César Magén, Hervé Roussel, Carmen Jiménez, Céline Ternon, Elena-Ioana Vatajelu, Mónica Burriel
The rapid development of brain-inspired computing requires new artificial components and architectures for its hardware implementation. In this regard, memristive devices emerged as potential candidates for artificial synapses because of their ability to emulate the plasticity of the biological synapses. In this work, the synaptic behavior of the TiN/La2NiO4+δ/Pt memristive devices based on thermally annealed La2NiO4+δ films is thoroughly investigated. Using electron energy loss spectroscopy (EELS), it is shown that post-deposition annealing using inert (Ar) or oxidizing (O2) atmospheres affects the interstitial oxygen content (δ) in the La2NiO4+δ films. Electrical characterization shows that both devices exhibit long-term potentiation/depression (LTP/LTD) and spike-timing-dependent plasticity (STDP). At the same time, the Ar annealed TiN/La2NiO4+δ/Pt device demonstrates filamentary-like behavior, fast switching, and low energy consumption. On the other hand, the O2 annealed TiN/La2NiO4+δ/Pt devices are forming-free, exhibiting interfacial-like resistive switching with slower kinetics. Finally, the simulation tools show that spiking neural network (SNN) architectures with weight updates based on the experimental data achieve high inference accuracy in the digit recognition task, which proves the potential of TiN/La2NiO4+δ/Pt devices for artificial synapse applications.
{"title":"Impact of the La2NiO4+δ Oxygen Content on the Synaptic Properties of the TiN/La2NiO4+δ/Pt Memristive Devices","authors":"Aleksandra Koroleva, Thoai-Khanh Khuu, César Magén, Hervé Roussel, Carmen Jiménez, Céline Ternon, Elena-Ioana Vatajelu, Mónica Burriel","doi":"10.1002/aelm.202400096","DOIUrl":"https://doi.org/10.1002/aelm.202400096","url":null,"abstract":"The rapid development of brain-inspired computing requires new artificial components and architectures for its hardware implementation. In this regard, memristive devices emerged as potential candidates for artificial synapses because of their ability to emulate the plasticity of the biological synapses. In this work, the synaptic behavior of the TiN/La<sub>2</sub>NiO<sub>4+δ</sub>/Pt memristive devices based on thermally annealed La<sub>2</sub>NiO<sub>4+δ</sub> films is thoroughly investigated. Using electron energy loss spectroscopy (EELS), it is shown that post-deposition annealing using inert (Ar) or oxidizing (O<sub>2</sub>) atmospheres affects the interstitial oxygen content (δ) in the La<sub>2</sub>NiO<sub>4+δ</sub> films. Electrical characterization shows that both devices exhibit long-term potentiation/depression (LTP/LTD) and spike-timing-dependent plasticity (STDP). At the same time, the Ar annealed TiN/La<sub>2</sub>NiO<sub>4+δ</sub>/Pt device demonstrates filamentary-like behavior, fast switching, and low energy consumption. On the other hand, the O<sub>2</sub> annealed TiN/La<sub>2</sub>NiO<sub>4+δ</sub>/Pt devices are forming-free, exhibiting interfacial-like resistive switching with slower kinetics. Finally, the simulation tools show that spiking neural network (SNN) architectures with weight updates based on the experimental data achieve high inference accuracy in the digit recognition task, which proves the potential of TiN/La<sub>2</sub>NiO<sub>4+δ</sub>/Pt devices for artificial synapse applications.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"120 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The human visual system provides important inspiration for designing energy-efficient and sophisticated artificial visual systems. However, integrating nonlinear preprocessing visual information and convolutional operations analogous to those of human in a single device is still in its infancy. In this work, a three-terminal 2D ferroelectric heterostructure consisting of α-In2Se3/WSe2 is proposed for designing optoelectronic neuromorphic device. In contrast to conventional ferroelectric materials, the narrow bandgap of the ferroelectric α-In2Se3 enables the device to perceive visible light directly. Nonlinearly preprocessing is adopted by bipolar cells in the retina and computer algorithms. In the device, similar function is achieved by modulating the energy band based on ferroelectricity. The results demonstrate the ability of the device to suppress noise, and the image recognition accuracy is increased from 75% to 92%. Convolutional neural networks play an important role to extract and compress the image information for human to respond to external environment in real time. Based on the unique coupling of ferroelectricity in α-In2Se3, the convolutional operation is imitated, thus allowing for reduction in image recognition time by 87%. The results provide a promising strategy to integrate diverse bio-inspired neuromorphic behaviors in a single device for artificial intelligence to process high-throughput visual information.
{"title":"Bio-Inspired Optoelectronic Neuromorphic Device Based on 2D vdW Ferroelectric Heterostructure for Nonlinearly Preprocessing Visual Information and Convolutional Operation","authors":"Feng Guo, Weng Fu Io, Zhaoying Dang, Yuqian Zhao, Sin-Yi Pang, Yifei Zhao, Xinyue Lao, Jianhua Hao","doi":"10.1002/aelm.202400528","DOIUrl":"https://doi.org/10.1002/aelm.202400528","url":null,"abstract":"The human visual system provides important inspiration for designing energy-efficient and sophisticated artificial visual systems. However, integrating nonlinear preprocessing visual information and convolutional operations analogous to those of human in a single device is still in its infancy. In this work, a three-terminal 2D ferroelectric heterostructure consisting of α-In<sub>2</sub>Se<sub>3</sub>/WSe<sub>2</sub> is proposed for designing optoelectronic neuromorphic device. In contrast to conventional ferroelectric materials, the narrow bandgap of the ferroelectric α-In<sub>2</sub>Se<sub>3</sub> enables the device to perceive visible light directly. Nonlinearly preprocessing is adopted by bipolar cells in the retina and computer algorithms. In the device, similar function is achieved by modulating the energy band based on ferroelectricity. The results demonstrate the ability of the device to suppress noise, and the image recognition accuracy is increased from 75% to 92%. Convolutional neural networks play an important role to extract and compress the image information for human to respond to external environment in real time. Based on the unique coupling of ferroelectricity in α-In<sub>2</sub>Se<sub>3</sub>, the convolutional operation is imitated, thus allowing for reduction in image recognition time by 87%. The results provide a promising strategy to integrate diverse bio-inspired neuromorphic behaviors in a single device for artificial intelligence to process high-throughput visual information.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"11 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xuanguang Zhang, Kaiqi Li, Jian Zhou, Stephen R. Elliott, Zhimei Sun
The ovonic threshold switching (OTS) effect, observed in chalcogenide glasses (CGs), involves a reversible transition from a high-resistive state (OFF state) to a conductive state (ON state) under an electric field. However, direct observation of the dynamic process of the OTS effect is challenging, leading to debate about the mechanism of the OTS effect. In this work, the OTS effect in GeSe2 glass is studied using ab initio molecular dynamics (AIMD) with electric fields. Before applying an electric field, the glass is in the OFF state. After applying electric fields of different strength, mid-gap states appear and band tail states get wider. Atomic chains composed of Se atoms and a small number of Ge atoms, which contribute to some mid-gap states, are formed by reversal of Peierls-like distortion. These atomic chains result in chain-like molecular orbitals. The percolation of the metastable channel through a reversal of the Peierls-like distortion process on the atomic chains can be considered the cause of the transition to the ON state in GeSe2 glass. Upon removing the electric field, the glass returns to the OFF state. This study provides insight into the conduction mechanism of CGs.
在铬化玻璃（CGs）中观察到的椭圆阈值转换（OTS）效应涉及在电场作用下从高电阻状态（OFF 状态）到导电状态（ON 状态）的可逆转换。然而，直接观察 OTS 效应的动态过程具有挑战性，这导致了有关 OTS 效应机理的争论。在这项研究中，我们利用带电场的原子分子动力学（ab initio molecular dynamics，AIMD）研究了 GeSe2 玻璃中的 OTS 效应。在施加电场之前，玻璃处于关断状态。施加不同强度的电场后，中隙态出现，带尾态变宽。由 Se 原子和少量 Ge 原子组成的原子链通过佩尔斯类畸变的反向作用形成，这些原子链对某些中隙态有贡献。这些原子链形成了链状分子轨道。原子链上的 Peierls 类畸变逆转过程导致的阶跃通道渗滤可被视为 GeSe2 玻璃过渡到导通态的原因。移除电场后，玻璃恢复到关态。这项研究有助于深入了解 CG 的传导机制。
{"title":"Ovonic Threshold Switching Induced by Reversal of Peierls-Like Distortion in GeSe2 Glass","authors":"Xuanguang Zhang, Kaiqi Li, Jian Zhou, Stephen R. Elliott, Zhimei Sun","doi":"10.1002/aelm.202400291","DOIUrl":"https://doi.org/10.1002/aelm.202400291","url":null,"abstract":"The ovonic threshold switching (OTS) effect, observed in chalcogenide glasses (CGs), involves a reversible transition from a high-resistive state (OFF state) to a conductive state (ON state) under an electric field. However, direct observation of the dynamic process of the OTS effect is challenging, leading to debate about the mechanism of the OTS effect. In this work, the OTS effect in GeSe<sub>2</sub> glass is studied using ab initio molecular dynamics (AIMD) with electric fields. Before applying an electric field, the glass is in the OFF state. After applying electric fields of different strength, mid-gap states appear and band tail states get wider. Atomic chains composed of Se atoms and a small number of Ge atoms, which contribute to some mid-gap states, are formed by reversal of Peierls-like distortion. These atomic chains result in chain-like molecular orbitals. The percolation of the metastable channel through a reversal of the Peierls-like distortion process on the atomic chains can be considered the cause of the transition to the ON state in GeSe<sub>2</sub> glass. Upon removing the electric field, the glass returns to the OFF state. This study provides insight into the conduction mechanism of CGs.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"21 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142306218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Sun, Jinkang Hu, Chi Chen, Xiaobo Wan, Youbing Mu
The development of polymeric dielectrics with a high dielectric constant is of great significance for flexible low-voltage organic field-effect transistors (OFETs). Herein, functional polyurethanes (PUs) with nitro and sulfobetaine zwitterionic groups are synthesized, and their electrical properties, mechanical properties, and the performances of OFET devices using these zwitterionic PUs as gate dielectrics are studied. Compared with sulfobetaine zwitterion-containing PUs, nitro-containing PUs (NO2-PUs) show higher dielectric constant up to 6.5. Both zwitterionic PUs enhance the OFET performances, while the effect of NO2-PU is more significant. Devices using NO2-PU-15 that contains 15 moL% nitro groups as the dielectric layer show the best performance and a threshold voltage (Vth) of as low as −0.02 V together with two orders’ increase of the mobility is observed, compared with the devices using PU without nitro groups. This study provides a new method to improve the dielectric constant of polymeric dielectrics, which is valuable for flexible/stretchable and wearable electronic devices.
{"title":"Functional Zwitterionic Polyurethanes as Gate Dielectrics for Organic Field-Effect Transistors","authors":"Qian Sun, Jinkang Hu, Chi Chen, Xiaobo Wan, Youbing Mu","doi":"10.1002/aelm.202400578","DOIUrl":"https://doi.org/10.1002/aelm.202400578","url":null,"abstract":"The development of polymeric dielectrics with a high dielectric constant is of great significance for flexible low-voltage organic field-effect transistors (OFETs). Herein, functional polyurethanes (PUs) with nitro and sulfobetaine zwitterionic groups are synthesized, and their electrical properties, mechanical properties, and the performances of OFET devices using these zwitterionic PUs as gate dielectrics are studied. Compared with sulfobetaine zwitterion-containing PUs, nitro-containing PUs (NO<sub>2</sub>-PUs) show higher dielectric constant up to 6.5. Both zwitterionic PUs enhance the OFET performances, while the effect of NO<sub>2</sub>-PU is more significant. Devices using NO<sub>2</sub>-PU-15 that contains 15 moL% nitro groups as the dielectric layer show the best performance and a threshold voltage (<i>V</i><sub>th</sub>) of as low as −0.02 V together with two orders’ increase of the mobility is observed, compared with the devices using PU without nitro groups. This study provides a new method to improve the dielectric constant of polymeric dielectrics, which is valuable for flexible/stretchable and wearable electronic devices.","PeriodicalId":110,"journal":{"name":"Advanced Electronic Materials","volume":"15 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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